223 research outputs found
Digital Transformation of Enterprise Learning: A Case Study of China Telecom
This study aimed to explore the digital transformation of enterprise learning. Through the case study of China Telecom, we studied how it transformed and its transformation dimensions
Student-centric Model of Learning Management System Activity and Academic Performance: from Correlation to Causation
In recent years, there is a lot of interest in modeling students' digital
traces in Learning Management System (LMS) to understand students' learning
behavior patterns including aspects of meta-cognition and self-regulation, with
the ultimate goal to turn those insights into actionable information to support
students to improve their learning outcomes. In achieving this goal, however,
there are two main issues that need to be addressed given the existing
literature. Firstly, most of the current work is course-centered (i.e. models
are built from data for a specific course) rather than student-centered;
secondly, a vast majority of the models are correlational rather than causal.
Those issues make it challenging to identify the most promising actionable
factors for intervention at the student level where most of the campus-wide
academic support is designed for. In this paper, we explored a student-centric
analytical framework for LMS activity data that can provide not only
correlational but causal insights mined from observational data. We
demonstrated this approach using a dataset of 1651 computing major students at
a public university in the US during one semester in the Fall of 2019. This
dataset includes students' fine-grained LMS interaction logs and administrative
data, e.g. demographics and academic performance. In addition, we expand the
repository of LMS behavior indicators to include those that can characterize
the time-of-the-day of login (e.g. chronotype). Our analysis showed that
student login volume, compared with other login behavior indicators, is both
strongly correlated and causally linked to student academic performance,
especially among students with low academic performance. We envision that those
insights will provide convincing evidence for college student support groups to
launch student-centered and targeted interventions that are effective and
scalable.Comment: 43 pages, 9 figures, 18 tables, Journal of Educational Data Mining
(Initial Submission
Exploring Impaired SERCA Pump-Caused Alternation Occurrence in Ischemia
Impaired sarcoplasmic reticulum (SR) calcium transport ATPase (SERCA) gives rise to Ca(2+) alternans and changes of the Ca2+release amount. These changes in Ca(2+) release amount can reveal the mechanism underlying how the interaction between Ca(2+) release and Ca(2+) uptake induces Ca(2+) alternans. This study of alternans by calculating the values of Ca(2+) release properties with impaired SERCA has not been explored before. Here, we induced Ca(2+) alternans by using an impaired SERCA pump under ischemic conditions. The results showed that the recruitment and refractoriness of the Ca(2+) release increased as Ca(2+) alternans occurred. This indicates triggering Ca waves. As the propagation of Ca waves is linked to the occurrence of Ca(2+) alternans, the "threshold" for Ca waves reflects the key factor in Ca(2+) alternans development, and it is still controversial nowadays. We proposed the ratio between the diastolic network SR (NSR) Ca content (Cansr) and the cytoplasmic Ca content (Ca i ) (Cansr/Ca i ) as the "threshold" of Ca waves and Ca(2+) alternans. Diastolic Cansr, Ca i , and their ratio were recorded at the onset of Ca(2+) alternans. Compared with certain Cansr and Ca i , the "threshold" of the ratio can better explain the comprehensive effects of the Ca(2+) release and the Ca(2+) uptake on Ca(2+) alternans onset. In addition, these ratios are related with the function of SERCA pumps, which vary with different ischemic conditions. Thus, values of these ratios could be used to differentiate Ca(2+) alternans from different ischemic cases. This agrees with some experimental results. Therefore, the certain value of diastolic Cansr/Ca i can be the better "threshold" for Ca waves and Ca(2+) alternans
Simulation on the Resistance of the Filter Media with Lattice Boltzmann Method
To simulate the resistance of fibrous air filter media it is first necessary to develop an accurate simulation model for the gas flow through the media structure. We present an approach making only one basic simplification to the media geometry to investigate the flow through micro-scale porous geometries with the slip and no-slip boundary conditions by means of Lattice Boltzmann Method (LBM). Computed air flow resistance predictions for two kinds of filter media are compared with experimental data and their validity is discussed
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